Art of cracking hydrocarbons



]. W. COAST ART OF CRAKING HYDROCARBONS.

APPLICATION FILED MAR. 21, 1917. RENEWED JUNE 14, 1920.

Patented Aug. 3, 1920.

UNITED STATES;

PATIENT oar-Ion.. v

JOHN W. COAST, JR, OF TULSA, ,OKLAHOMA, ASSIGNOR TO THE PROCESS COMPANY, A I

CORPORATION OF I IABYLAND.

Anr or enema mnocrmisons.

- Application filed March 27, 1917, Serial No. 157,629.; Renewed June 14, 1920. Serial No. 389,008.

To all whom it may concern:

Be it known that I, J OHN W. CoAsr, J r., a citizen of the United States of America, a resident of Tulsa, in'the county of Tulsa, State of Oklahoma, have invented certain ,new and useful Improvements-in the Art of Cracking Hydrocarbons, of-which the foli lowing is a full, clear, and exact description,

reference being had to the accompanying drawings, forming a part of this specificaton. Y I

My invention relates to improvements in the art of cracking petroleum hydrocarbons,

one of the objects being to protect cracking stills from the injurious effects of cokeforming substances which tend to accumulate on the hottest parts of the stills. Th1s v feature of the invention increases the efficiency of a cracking apparatus by circulating the coke, or carbon, away from the point at which heat is transmitted to the still, thus permitting the heat to be transmitted freely from the still to the oil, at the V same time avoiding the danger of overheat- Figure I Is a diagrammatical view, (partly in section, of a crackingapparatus a for use in carrying out my method.

Fig. II is a. diagrammatical perspective view, showing a battery of cracking stills connected by overflow conductors. Fig. III is. an enlarged verti illustrating one of the coke-tra s.

To illustrate the. invention, have shown a battery of cracking stills, designated 1, 2, 3 and 4:, res ectively.. Each cracking still is apted arranged a ove .a heating chamber 5 and.

connected by means of an air cooled'vapor pipe 6 to a reflux condenser 7, said condenser- 7 being connected by means of a vapor ipe 8 to a' water cooled condensing coil 9, rom

which the low boiling point product is recovered. Each vapor "pipe 8 is preferably 1 section provided a valve 10 for regulating the pressure.

The apparatus I have shown is particularly adapted for use in cracking high boiling point products of distillation, such, for example, as the distillates or residues resulting from the distillation of petroleum. The pressure in the battery of stills is preferably greater than 50 pounds per square inch, and. the temperature of the contents of the stills'preferabl ranges from about 600 F. to 800 F. through the bottoms of the stills-so asto vaporize and crackv the oil contained therein. The heavy coke-formin fractions drop by gravity in the liquid an, tend to accumulate on the hot still bottoms.

The object of this invention is to remove the coke-forming fractions by causing the liquid to overflow from the bottom of one still, through a coke-trap and then into another still, the coke-forming substance being thus circulated from the lower portion of the first mentioned still and deposited in the coke-trap. The Oll' t0 .be cracked. is forced through a pipe 11 and intothe still 1, from which it" overflows and circulates into the other stills. The different stills are eat is transmitted directly Specification 01a ream. J P t t 3, 1920 connected together in series, as shown in i .Fig. II. An overflow conductor .12 leads from the lower portion ofthe still 1 to the lower portion of a coke-trap .13, and the upper portion of the coke-trap is connected to the still 2 by means of a pipe 14. The

liquid overflowing from the still 1, passes out through the pipe 12, and is discharged into the lower portion of the coke-trap 13. The heavy coke-forming fractions are mitted to accumulate at the bottom of the coke-trap, and the lighter liquid overflows from the upper portion of the coke-trap and circulates into the still 2. A large percentage of the heavy,- coke-forming substance is thus conducted tothe coke-trap 13, where it will not in any way injure or affect the cracking apparatus. The coke,; or tarry coke-forming substance, may be remov from the'trap 13 by opening a valve 15 in the discharge pipe 16... v The liquld overflowing from the lower portion of the still 2, passes through a pipe 12 and into a coke-trap 13, the relatively perlight liquid being permitted to overflow from said coke-trap 13 through a pipe 14' and into the still 3. The stills 3'and 4 are connected by means of an overflow pipe 12, a coke-trap13 and an overflow pipe 14. The overflow conductors place the different stills in free communication with each other, and a uniform pressure is therefore maintained inall ofthe stills. This pressure is also maintained in the coke-traps and overflow pipes. All of the overflowing liquid must circulate through a coke-trap, wherein the heavy coke-forming substance will drop by gravity instead of passing from one still to another.

I claim:

In the art of crackinghydrocarbons, the method which comprises maintaining the contents of a battery of horizontal c lindrical cracking stills under pressure, an in free communication with each other so as to v equalize the pressure in the several stills, introducing the oil to'be cracked into the battery of stills by conducting the oil into one of the stills and permitting it to overflow in a liquid state into the other stills, the overflowing oil being conducted from the lower portion of one still through a coketrap and into another still so as to carry coke-forming fractions from the bottom of the overflowing still to the coke trap, and

heating the bottoms ofthe stills to maintain the oil at a cracking temperature.

In testimony that 'Lclaim the foregoing I hereunto aflix my signature.

JOHN W. COAST, JR. 

